"ains fluid ??? ??? ??? vagus nerve the tenth cranial nerve that innervates digestive organs, heart and other areas ??? ??? ??? vein a blood vessel that carries blood back to the heart from the capillaries ??? ??? ??? ventral root the basal branch of each spinal nerve; carries motor neurons ??? ??? ??? ventricle the more muscular chamber(s) of the heart that pump blood to the lungs and to the rest" . . . .